The present invention relates generally to construction of roofs for buildings, and, more particularly, to methods for mounting preassembled rafters to a building to support a site-built roof surface.
In construction of either mobile or static buildings, roofs have generally been built by either the use of xe2x80x9cstick builtxe2x80x9d rafters or prefabricated rafter trusses. In either case, the rafters are usually first positioned with respect to each other and the lower portion of the building they are to cover along the entire area to be covered by the roof. Once all or substantially all of the rafters are in place, the structural material for the roof surface, often sheets of plywood, are attached to the rafters.
Prefabricated rafter trusses are becoming more and more commonly used due to the reduced cost and construction time they can provide. By xe2x80x9cprefabricated,xe2x80x9d it is meant that the rafter trusses are initially assembled from multiple structural members, usually 2xc3x974 lumber members, at a location remote from the site of the building being constructed, and then transported to the construction site for installation on the building as a completed unit via a crane or like machinery.
Unlike with stick built roofs, when using prefabricated rafter trusses, there is typically no central ridgebeam to which they are mounted and spaced as each rafter is put in place. Given the weight and size of such trusses, it is important to maintain proper orientation and spacing as each truss is brought to the roof. Previously, workers have had to carefully measure the spacing and plumb of each truss as it was lifted and placed over the building by the crane. Once satisfied of the truss location, full lengths of construction grade 2xc3x974 lumber were typically nailed to each adjacent truss to temporarily hold it in place. Unfortunately, in such situations there is often no safe platform for the roof workers to stand on when holding that relatively large and heavy 2xc3x974 at the ready, measuring the truss position and then holding the 2xc3x974 in place while nailing it to each of the trusses. Thus, some imprecision could be introduced in truss position or hazardous environment created for the worker as a result, particularly during placement of the initial trusses.
Further, the 2xc3x974s were only a temporary form of truss retention. As the sheets of plywood were permanently secured to each truss, additional labor was required to have the 2xc3x974s removed and set aside. Thus, nail perforated lumber was often found strewn about the workplace, creating yet another hazard for workers, visitors and casual trespassers frequently attracted to the construction site. In addition, this lumber was often permanently discarded as waste and not used for any other purpose, if for no other reason than the effort required to remove the nails initially placed in it for the trusses.
Obviously, in each aspect, there have been methods of correcting these deficiencies of construction practice. Unfortunately, it was often the case that the high cost of labor time to correct these deficiencies effectively precluded remedy by that route.
Accordingly, it is an object of the present invention to provide an improved method and apparatus from the construction of building roofs. Other objects include the provision of a roof construction arrangement that:
a. is less costly in terms of both material and labor expenses,
b. utilizes less hazardous construction methods,
c. provides more accurate placement and retention of roof rafters,
d. is less wasteful of environmental resources, and
e. is easier to apply and can be permanently affixed to the building.
These and other objects are attained by the provision of a rafter assembly for joining each adjacent pair of trusses by linkage members that precisely define the predetermined spacing required between the trusses, support the trusses against relative motion apart, and include integral truss penetrating projections for initial attachment and conventional fastener alignment means for accommodating permanent connection fasteners. Further, the linkage members are configured and mountable on the trusses so as to provide no interference with the attachment of the structural members creating the roof surface.
Other objects, advantages and novel features of the present invention will now become readily apparent to those of skill in this technology from consideration of the attached drawings and detailed description of certain preferred embodiments.